Concrete for a 2-Car Garage Floor
Free calculator with pre-filled dimensions • Updated March 2026
A 24×24 garage floor at 6 inches thick needs 10.67 cubic yards of concrete — a full truck load.
Open calculator with these dimensions →2-Car Garage Floor: Complete Concrete Guide
A standard 2-car garage measures 24×24 feet with a 6-inch thick concrete floor. At 10.67 cubic yards, this is a significant pour requiring a ready-mix truck, proper reinforcement, and usually a professional crew.
Material Requirements
| Material | Quantity | Cost (2026) |
|---|---|---|
| Ready-mix 4,000 PSI | 11.7 yd³ (with 10% extra) | $1,400–$2,000 |
| Compacted gravel base (6") | 10.7 yd³ | $215–$375 |
| #4 rebar (12" OC grid) | 24×24 grid = ~100 pieces | $350–$600 |
| 2×6 form lumber | 16 boards (12-foot) | $96–$144 |
| Vapor barrier (6-mil poly) | 1 roll (20×25) | $35–$50 |
Total DIY cost: $2,100–$3,200. Professional: $5,500–$9,000.
Garage-Specific Requirements
- Vapor barrier: Garages need 6-mil polyethylene under the slab to prevent moisture migration. This protects stored items and prevents efflorescence.
- Slope toward door: 1/8" per foot toward the garage door opening for drainage. On a 24-foot depth, that is 3 inches of total fall.
- Thickened edge: Where the slab meets the garage door opening, thicken to 8–10 inches and add extra rebar. This "apron" takes the most abuse.
- Anchor bolt placement: If the garage walls sit on this slab, install J-bolts before the concrete sets (typically 1/2" × 10" bolts at 6-foot intervals).
Pro Tips
- Epoxy floor coating: Plan for an epoxy coating application after 28 days of curing. This protects against oil stains, road salt, and tire marks. Budget $300–$600 for a DIY 2-car garage kit.
- Control joints: A 24×24 garage needs joints creating sections no larger than 12×12. Minimum of one joint each direction.
- Don't pour in freezing weather. Garage floors must cure above 50°F for proper strength development. In cold climates, time the pour for spring or fall.
Frequently Asked Questions
How much concrete for a 2-car garage?
A standard 24×24 foot, 2-car garage floor at 6 inches thick requires 10.67 cubic yards. With 10% extra for waste, order 11.7 cubic yards — about a full ready-mix truck load.
How thick should a garage floor be?
Minimum 6 inches for vehicle traffic. Some builders use 4 inches with thickened edges, but 6 inches throughout is the modern standard for residential garages. Use 4,000 PSI concrete.
Do I need a vapor barrier under a garage floor?
Yes. A 6-mil polyethylene vapor barrier prevents moisture from migrating through the slab, which causes efflorescence, mold, and damage to stored items. Overlap seams by 6 inches and tape.